title: Impact of fluoroscopy unit on the accuracy of a magnet-based electroanatomic mapping and navigation system: an in vitro and in vivo validation study.
abstract: BACKGROUND
  During mapping and ablation procedures, the movement of large ferromagnetic items (i.e., fluoroscopic equipment) introduce heterogeneities in the electromagnetic field, which may affect the accuracy of electromagnet-based navigation. We aimed to assess the impact of common periprocedural fluoroscopic equipment movement on the accuracy of an electromagnet-based navigation system.
  
  
  RESULTS
  The impact of fluoroscopic equipment movement on the accuracy of the Carto® 3 System (Biosense Webster, Inc., Diamond Bar, CA, USA) was assessed both in vitro (n = 20 patients, phantom model) and in vivo (n = 18 patients). Location recordings were obtained with unchanged catheter position for fluoroscopic equipment rotational movements (RMs) and maximal to closest distance (MD to CD) to phantom/patient. The effects of both single- and biplane fluoroscopy were assessed. In vitro, the movement of fluoroscopic equipment resulted in an average catheter location estimation error of 0.8 mm (interquartile range 0.3-1.3). The maximal location estimation errors with MD to CD movement and RM were 2.3 mm and 1.3 mm, respectively. Changing from single-plane to biplane setup resulted in an average location estimation change of 1.5 mm (maximum 2.1). Larger location changes were observed in vivo (2.9 mm vs 0.8 mm, P < 0.0001) with 28.7% of these exceeded 4 mm versus none of the in vitro measurements (P < 0.0001).
  
  
  CONCLUSIONS
  Although fluoroscopy manipulation affected the accuracy of the Carto® 3 System, the in vitro data suggest that these inaccuracies are likely of limited clinical consequences. The larger in vivo inaccuracies are most likely due to nonferromagnetic interferences, such as respiratory or cardiac movements.
authors.affiliation: Maryland Arrhythmia and Cardiology Imaging Group (MACIG), Division of Cardiology, University of Maryland, Baltimore, Maryland.
authors.forename: Ghada
authors.initials: G
authors.lastname: Ahmad
authors.forename: Ayman A
authors.initials: AA
authors.lastname: Hussein
authors.forename: Olurotimi
authors.initials: O
authors.lastname: Mesubi
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
authors.forename: Hanaa
authors.initials: H
authors.lastname: Ferieg
authors.forename: Mervat A
authors.initials: MA
authors.lastname: Elmaaty
authors.forename: Amal
authors.initials: A
authors.lastname: Hamdy
authors.forename: Kelechi
authors.initials: K
authors.lastname: Ego-Osuala
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jimenez
authors.forename: Vincent
authors.initials: V
authors.lastname: See
authors.forename: Anastasios
authors.initials: A
authors.lastname: Saliaris
authors.forename: Stephen
authors.initials: S
authors.lastname: Shorofsky
authors.forename: Timm
authors.initials: T
authors.lastname: Dickfeld
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D018780:Body Surface Potential Mapping / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005471:Fluoroscopy / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D059346:Magnets; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: arrhythmias; mapping; navigation systems